Bottles of flexible plastics material, such as biaxially oriented polyethylene terephthalate (PET), are coming into favor because they are lighter in weight and more resistant to breakage due to shock or impact than bottles made of glass. However, these PET bottles, when formed by injection blow molding, have bottoms which are unavoidably convex or rounded and are therefore incapable of standing in a stable, upright position. The principle object of this invention is to provide a supporting base cup for application to the bottom of the bottle which snaps on readily and will stay on despite normal and even excessively abnormal handling, or being dropped on a hard surface or otherwise subjected to heavy shock or impact. The cup and also the bottom of the bottle are specially formed to hold the cup firmly applied, without the need for an adhesive.
Other objects and features of the invention will become more apparent as the following description proceeds, especially when considered in conjunction with the accompanying drawings.